He said: "Her Majesty spoke recently of how, since her first visit here 60 years ago, she has been privileged to witness Australia's growing economy and flowering self-confidence.

"For Catherine, Harry and me, born in the early 80s, we've never known anything else – Australia and Australians have always been for us a beacon of confidence, creativity in the arts and sporting ability."

William's eight-month-old son has been the star attraction of the trip and won the heart of the Kiwis.

His proud father could not help mentioning the baby prince, saying: "I don't think I could finish these brief words to you without mentioning one other family member, George, who is now busy forging his own link with Australia.

"Catherine and I were very grateful for the many kind messages and gifts from across the country that we received when George was born."

The eight-month-old prince is expected to make an appearance on Sunday when his parents take him to Taronga zoo in Sydney where an enclosure housing bilbys - a rabbit-like marsupial - will be named after him.

William joked: "I suspect George's first word might be 'bilby' - only because koala is harder to say. We really look forward to our time here together as a family."